On 1/29/20 7:20 PM, Jens Axboe wrote: > On 1/29/20 6:08 PM, Jens Axboe wrote: >> On 1/29/20 10:34 AM, Jens Axboe wrote: >>> On 1/29/20 7:59 AM, Jann Horn wrote: >>>> On Tue, Jan 28, 2020 at 8:42 PM Jens Axboe <axboe@xxxxxxxxx> wrote: >>>>> On 1/28/20 11:04 AM, Jens Axboe wrote: >>>>>> On 1/28/20 10:19 AM, Jens Axboe wrote: >>>> [...] >>>>>>> #1 adds support for registering the personality of the invoking task, >>>>>>> and #2 adds support for IORING_OP_USE_CREDS. Right now it's limited to >>>>>>> just having one link, it doesn't support a chain of them. >>>> [...] >>>>> I didn't like it becoming a bit too complicated, both in terms of >>>>> implementation and use. And the fact that we'd have to jump through >>>>> hoops to make this work for a full chain. >>>>> >>>>> So I punted and just added sqe->personality and IOSQE_PERSONALITY. >>>>> This makes it way easier to use. Same branch: >>>>> >>>>> https://git.kernel.dk/cgit/linux-block/log/?h=for-5.6/io_uring-vfs-creds >>>>> >>>>> I'd feel much better with this variant for 5.6. >>>> >>>> Some general feedback from an inspectability/debuggability perspective: >>>> >>>> At some point, it might be nice if you could add a .show_fdinfo >>>> handler to the io_uring_fops that makes it possible to get a rough >>>> overview over the state of the uring by reading /proc/$pid/fdinfo/$fd, >>>> just like e.g. eventfd (see eventfd_show_fdinfo()). It might be >>>> helpful for debugging to be able to see information about the fixed >>>> files and buffers that have been registered. Same for the >>>> personalities; that information might also be useful when someone is >>>> trying to figure out what privileges a running process actually has. >>> >>> Agree, that would be a very useful addition. I'll take a look at it. >> >> Jann, how much info are you looking for? Here's a rough start, just >> shows the number of registered files and buffers, and lists the >> personalities registered. We could also dump the buffer info for >> each of them, and ditto for the files. Not sure how much verbosity >> is acceptable in fdinfo? >> >> Here's the test app for personality: >> >> # cat 3 >> pos: 0 >> flags: 02000002 >> mnt_id: 14 >> user-files: 0 >> user-bufs: 0 >> personalities: >> 1: uid=0/gid=0 > > Here's one that adds the registered buffers and files as well. So > essentially this shows any info on the registered parts. Output of this version, using t/io_uring from fio: # cat /proc/338/fdinfo/4 pos: 0 flags: 02000002 mnt_id: 14 user-files: 1 0: nvme0n1p2 user-bufs: 128 0: 55ea44b52000/4096 1: 55ea44b54000/4096 2: 55ea44b56000/4096 3: 55ea44b58000/4096 4: 55ea44b5a000/4096 5: 55ea44b5c000/4096 6: 55ea44b5e000/4096 7: 55ea44b60000/4096 8: 55ea44b62000/4096 9: 55ea44b64000/4096 10: 55ea44b66000/4096 11: 55ea44b68000/4096 12: 55ea44b6a000/4096 13: 55ea44b6c000/4096 14: 55ea44b6e000/4096 15: 55ea44b70000/4096 16: 55ea44b72000/4096 17: 55ea44b74000/4096 18: 55ea44b76000/4096 19: 55ea44b78000/4096 20: 55ea44b7a000/4096 21: 55ea44b7c000/4096 22: 55ea44b7e000/4096 23: 55ea44b80000/4096 24: 55ea44b82000/4096 25: 55ea44b84000/4096 26: 55ea44b86000/4096 27: 55ea44b88000/4096 28: 55ea44b8a000/4096 29: 55ea44b8c000/4096 30: 55ea44b8e000/4096 31: 55ea44b90000/4096 32: 55ea44b92000/4096 33: 55ea44b94000/4096 34: 55ea44b96000/4096 35: 55ea44b98000/4096 36: 55ea44b9a000/4096 37: 55ea44b9c000/4096 38: 55ea44b9e000/4096 39: 55ea44ba0000/4096 40: 55ea44ba2000/4096 41: 55ea44ba4000/4096 42: 55ea44ba6000/4096 43: 55ea44ba8000/4096 44: 55ea44baa000/4096 45: 55ea44bac000/4096 46: 55ea44bae000/4096 47: 55ea44bb0000/4096 48: 55ea44bb2000/4096 49: 55ea44bb4000/4096 50: 55ea44bb6000/4096 51: 55ea44bb8000/4096 52: 55ea44bba000/4096 53: 55ea44bbc000/4096 54: 55ea44bbe000/4096 55: 55ea44bc0000/4096 56: 55ea44bc2000/4096 57: 55ea44bc4000/4096 58: 55ea44bc6000/4096 59: 55ea44bc8000/4096 60: 55ea44bca000/4096 61: 55ea44bcc000/4096 62: 55ea44bce000/4096 63: 55ea44bd0000/4096 64: 55ea44bd2000/4096 65: 55ea44bd4000/4096 66: 55ea44bd6000/4096 67: 55ea44bd8000/4096 68: 55ea44bda000/4096 69: 55ea44bdc000/4096 70: 55ea44bde000/4096 71: 55ea44be0000/4096 72: 55ea44be2000/4096 73: 55ea44be4000/4096 74: 55ea44be6000/4096 75: 55ea44be8000/4096 76: 55ea44bea000/4096 77: 55ea44bec000/4096 78: 55ea44bee000/4096 79: 55ea44bf0000/4096 80: 55ea44bf2000/4096 81: 55ea44bf4000/4096 82: 55ea44bf6000/4096 83: 55ea44bf8000/4096 84: 55ea44bfa000/4096 85: 55ea44bfc000/4096 86: 55ea44bfe000/4096 87: 55ea44c00000/4096 88: 55ea44c02000/4096 89: 55ea44c04000/4096 90: 55ea44c06000/4096 91: 55ea44c08000/4096 92: 55ea44c0a000/4096 93: 55ea44c0c000/4096 94: 55ea44c0e000/4096 95: 55ea44c10000/4096 96: 55ea44c12000/4096 97: 55ea44c14000/4096 98: 55ea44c16000/4096 99: 55ea44c18000/4096 100: 55ea44c1a000/4096 101: 55ea44c1c000/4096 102: 55ea44c1e000/4096 103: 55ea44c20000/4096 104: 55ea44c22000/4096 105: 55ea44c24000/4096 106: 55ea44c26000/4096 107: 55ea44c28000/4096 108: 55ea44c2a000/4096 109: 55ea44c2c000/4096 110: 55ea44c2e000/4096 111: 55ea44c30000/4096 112: 55ea44c32000/4096 113: 55ea44c34000/4096 114: 55ea44c36000/4096 115: 55ea44c38000/4096 116: 55ea44c3a000/4096 117: 55ea44c3c000/4096 118: 55ea44c3e000/4096 119: 55ea44c40000/4096 120: 55ea44c42000/4096 121: 55ea44c44000/4096 122: 55ea44c46000/4096 123: 55ea44c48000/4096 124: 55ea44c4a000/4096 125: 55ea44c4c000/4096 126: 55ea44c4e000/4096 127: 55ea44c50000/4096 -- Jens Axboe
